but first, here's nbc's lee cowan. >> reporter: baby gabriel's first birthday is now less than two weeks away and no one knows whether he is alive to celebrate it or not. his mother, elizabeth johnson, is behind bars, charged with gabriel's kidnapping. his father, logan, has been looking for gabriel for four long months but hasn't found a trace. >> i want to believe that he is alive. i just want her to tell the truth. >> reporter: police say it all started last december when johnson allegedly took gabriel from his home in tempe, arizona and drove all the way to san antonio, texas. it was there she offered bone-chilling news to gabriel's father. police say she told him that she had smothered gabriel and had thrown his body in a san antonio dumpster. investigators, along with a team of volunteers, sorted through more than 4,000 tons of trash looking for clues. >> we don't want to leave any of it uncovered. >> reporter: but after more than two weeks, found nothing that hinted of a homicide. that may have backed up gabriel's mom's other story. investigators say she toll them that she had act